Prefabricated Vertical Drains (PVDs) are typically used for embankment construction over saturate... more Prefabricated Vertical Drains (PVDs) are typically used for embankment construction over saturated soft cohesive soil deposits to accelerate consolidation and reduce construction time in the field. PVDs accelerate consolidation of thick soil deposits by reducing the drainage path from tens of meters to 1-2 meters depending on PVD spacing in the field. Current design methodologies typically consider the increase of shear strength due to accelerated consolidation, but still use undrained shear strength for the entire cohesive soil layer even after PVD’s are installed. However, for cases in which PVDs are closely spaced, which allows excess pore water pressure to dissipate relatively fast, the assumption of undrained conditions for design may be overly conservative and, in some cases, this assumption may render an embankment construction unfeasible, unless additional ground improvement techniques are used to significantly enhance the foundation strength. This paper presents a Hybrid Dr...
Abstract Traditional valuation methods such as net present value (NPV) utilize increased discount... more Abstract Traditional valuation methods such as net present value (NPV) utilize increased discount rates to account for risk, in the process introducing a time bias effect that promotes short-termism. Application of NPV often discourages much needed infrastructure projects that require large capital investments yet are slow to generate positive cashflows. NPV also downplays the significance of future liabilities and can lead to risk misallocation amongst investment partners and stakeholders. The decoupled net present value (DNPV) method introduces the risk-as-a-cost concept that prices the risk of obtaining lower-than-expected cashflows and thus represents investors’ compensation for bearing such risks. Capturing the loss-aversion attitudes described by prospect theory, DNPV provides a transparent and consistent valuation framework for long-term investments by: (i) calculating expected values of cashflow components using their probability characterizations, (ii) defining the cost of risk (market and non-market) as the expected downside value, (iii) subtracting/adding the cost of risk from/to expected revenues/expenditures, and (iv) discounting the results using risk-free rates. DNPV’s power is illustrated by re-analyzing a 42-year toll-road concession initially evaluated using NPV and real options. The case study shows how explicit risk quantifications could be used to better structure the concession and reallocate risks among stakeholders.
... contracts with a percentage fee, there is potential for moral hazard since contractors earn a... more ... contracts with a percentage fee, there is potential for moral hazard since contractors earn a ... 2 shows the price variation of asphalt cement, along with the consumer index price (CPI), for ... Hence, using CPI as a proxy for the market risk associated with asphalt cement prices can ...
Diverse studies have been made about the chemical and structural characterization of the containe... more Diverse studies have been made about the chemical and structural characterization of the contained minerals in lateritics profiles, opening the possibility to study morphological transformations of these products along these profiles. At the present time the mechanism of formation of the ...
... día más fortaleza y perseverancia. A mi madre Maria Vanegas, a mi padre Julio Solano ya mi he... more ... día más fortaleza y perseverancia. A mi madre Maria Vanegas, a mi padre Julio Solano ya mi hermana Melissa Solano, por haberme dado aliento a lo largo de mi carrera universitaria, por brindarme su apoyo, y por ser ... Manuel, Dalila, Mario, Olymar, Sra. Miriam, Beatriz. ...
Photonics 2010: Tenth International Conference on Fiber Optics and Photonics, 2010
Applications of polymer post processing of silicon on insulator (SoI) devices are demonstrated. P... more Applications of polymer post processing of silicon on insulator (SoI) devices are demonstrated. Polymer overlays on SoI nanophotonic circuits are used, on the one hand, to improve optical antenna transception for an any-one-to-all array and, on the other hand, a similar photodefinable coating is used to passively tune the dispersive characteristics of waveguides embedded in photonic crystals. Discussion is given
2013 IEEE Global Humanitarian Technology Conference (GHTC), 2013
ABSTRACT This paper addresses the use of a VoIP communication service running on a Wi-Fi-based ne... more ABSTRACT This paper addresses the use of a VoIP communication service running on a Wi-Fi-based network in the Peruvian Rainforest to enable a cooperative network among producers, buyers and transporters of agricultural products. As a result, uncertainties in a geographically isolated imperfect agricultural market will be reduced, leading to a more efficient use of scarce resources, an increase of farmers' incomes, and more competitive prices of products in urban markets. This project involves enabling access to agricultural product information from buyers in urban areas to farmers in rural villages, as well as transporters and middlemen. The deployment of the Wi-Fi network began in 2007. This network, a 445 km long Wi-Fi Long Distance-based network, was deployed by the Rural Telecommunications Research Group and the Spanish-Americas Health Link (EHAS) Foundation to support telemedicine programs. The deployed network and excess bandwidth makes it possible to continue promoting development in this area by allowing coexistence with other services such as the proposed VoIP enabled cooperative network for commerce of agricultural products. To achieve this end, challenges include: 1) designing an appropriate framework to enable the cooperative network among participants, 2) designing appropriate friendly end-user technology for first-time technology users, and 3) designing an appropriate business model which ensures a sustainable growing service. Using the VoIP service as a tool to enable affordable communication for this agricultural initiative will allow interaction among producers, buyers and transporters located hundreds of kilometers apart and open unprecedented choices for them to offer and trade products, generating innovative practices tailored for the local conditions.
1. Introduction Silicon-based nanophotonic interconnection networks are promising for intra-chip ... more 1. Introduction Silicon-based nanophotonic interconnection networks are promising for intra-chip communication [1]. The re-quirements of many-core processor interconnections systems are stringent. Such a network will require many wave-length division (WDM) channels ...
... Two discussions of a paper with the aforementioned title by Espinoza, Bourdeau, and Muhunthan... more ... Two discussions of a paper with the aforementioned title by Espinoza, Bourdeau, and Muhunthan, published in this journal (Volume 120, Number 7 ... Discussers Wright and Duncan also comment specifically on case 6 of example 2, attributing the unusually large value of safety ...
Prefabricated Vertical Drains (PVDs) are typically used for embankment construction over saturate... more Prefabricated Vertical Drains (PVDs) are typically used for embankment construction over saturated soft cohesive soil deposits to accelerate consolidation and reduce construction time in the field. PVDs accelerate consolidation of thick soil deposits by reducing the drainage path from tens of meters to 1-2 meters depending on PVD spacing in the field. Current design methodologies typically consider the increase of shear strength due to accelerated consolidation, but still use undrained shear strength for the entire cohesive soil layer even after PVD’s are installed. However, for cases in which PVDs are closely spaced, which allows excess pore water pressure to dissipate relatively fast, the assumption of undrained conditions for design may be overly conservative and, in some cases, this assumption may render an embankment construction unfeasible, unless additional ground improvement techniques are used to significantly enhance the foundation strength. This paper presents a Hybrid Dr...
Abstract Traditional valuation methods such as net present value (NPV) utilize increased discount... more Abstract Traditional valuation methods such as net present value (NPV) utilize increased discount rates to account for risk, in the process introducing a time bias effect that promotes short-termism. Application of NPV often discourages much needed infrastructure projects that require large capital investments yet are slow to generate positive cashflows. NPV also downplays the significance of future liabilities and can lead to risk misallocation amongst investment partners and stakeholders. The decoupled net present value (DNPV) method introduces the risk-as-a-cost concept that prices the risk of obtaining lower-than-expected cashflows and thus represents investors’ compensation for bearing such risks. Capturing the loss-aversion attitudes described by prospect theory, DNPV provides a transparent and consistent valuation framework for long-term investments by: (i) calculating expected values of cashflow components using their probability characterizations, (ii) defining the cost of risk (market and non-market) as the expected downside value, (iii) subtracting/adding the cost of risk from/to expected revenues/expenditures, and (iv) discounting the results using risk-free rates. DNPV’s power is illustrated by re-analyzing a 42-year toll-road concession initially evaluated using NPV and real options. The case study shows how explicit risk quantifications could be used to better structure the concession and reallocate risks among stakeholders.
... contracts with a percentage fee, there is potential for moral hazard since contractors earn a... more ... contracts with a percentage fee, there is potential for moral hazard since contractors earn a ... 2 shows the price variation of asphalt cement, along with the consumer index price (CPI), for ... Hence, using CPI as a proxy for the market risk associated with asphalt cement prices can ...
Diverse studies have been made about the chemical and structural characterization of the containe... more Diverse studies have been made about the chemical and structural characterization of the contained minerals in lateritics profiles, opening the possibility to study morphological transformations of these products along these profiles. At the present time the mechanism of formation of the ...
... día más fortaleza y perseverancia. A mi madre Maria Vanegas, a mi padre Julio Solano ya mi he... more ... día más fortaleza y perseverancia. A mi madre Maria Vanegas, a mi padre Julio Solano ya mi hermana Melissa Solano, por haberme dado aliento a lo largo de mi carrera universitaria, por brindarme su apoyo, y por ser ... Manuel, Dalila, Mario, Olymar, Sra. Miriam, Beatriz. ...
Photonics 2010: Tenth International Conference on Fiber Optics and Photonics, 2010
Applications of polymer post processing of silicon on insulator (SoI) devices are demonstrated. P... more Applications of polymer post processing of silicon on insulator (SoI) devices are demonstrated. Polymer overlays on SoI nanophotonic circuits are used, on the one hand, to improve optical antenna transception for an any-one-to-all array and, on the other hand, a similar photodefinable coating is used to passively tune the dispersive characteristics of waveguides embedded in photonic crystals. Discussion is given
2013 IEEE Global Humanitarian Technology Conference (GHTC), 2013
ABSTRACT This paper addresses the use of a VoIP communication service running on a Wi-Fi-based ne... more ABSTRACT This paper addresses the use of a VoIP communication service running on a Wi-Fi-based network in the Peruvian Rainforest to enable a cooperative network among producers, buyers and transporters of agricultural products. As a result, uncertainties in a geographically isolated imperfect agricultural market will be reduced, leading to a more efficient use of scarce resources, an increase of farmers' incomes, and more competitive prices of products in urban markets. This project involves enabling access to agricultural product information from buyers in urban areas to farmers in rural villages, as well as transporters and middlemen. The deployment of the Wi-Fi network began in 2007. This network, a 445 km long Wi-Fi Long Distance-based network, was deployed by the Rural Telecommunications Research Group and the Spanish-Americas Health Link (EHAS) Foundation to support telemedicine programs. The deployed network and excess bandwidth makes it possible to continue promoting development in this area by allowing coexistence with other services such as the proposed VoIP enabled cooperative network for commerce of agricultural products. To achieve this end, challenges include: 1) designing an appropriate framework to enable the cooperative network among participants, 2) designing appropriate friendly end-user technology for first-time technology users, and 3) designing an appropriate business model which ensures a sustainable growing service. Using the VoIP service as a tool to enable affordable communication for this agricultural initiative will allow interaction among producers, buyers and transporters located hundreds of kilometers apart and open unprecedented choices for them to offer and trade products, generating innovative practices tailored for the local conditions.
1. Introduction Silicon-based nanophotonic interconnection networks are promising for intra-chip ... more 1. Introduction Silicon-based nanophotonic interconnection networks are promising for intra-chip communication [1]. The re-quirements of many-core processor interconnections systems are stringent. Such a network will require many wave-length division (WDM) channels ...
... Two discussions of a paper with the aforementioned title by Espinoza, Bourdeau, and Muhunthan... more ... Two discussions of a paper with the aforementioned title by Espinoza, Bourdeau, and Muhunthan, published in this journal (Volume 120, Number 7 ... Discussers Wright and Duncan also comment specifically on case 6 of example 2, attributing the unusually large value of safety ...
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Papers by David Espinoza